Organic solvent-free film-forming compositions, multi-layer composite coatings, and related methods

Abstract

Provided is a film-forming composition substantially free of organic solvent which includes an aqueous dispersion of polymeric microparticles prepared by emulsion polymerization of a monomeric composition containing (1) at least 10 percent by weight of one or more vinyl aromatic compounds; (2) 0.1 to 10 percent by weight of one or more carboxylic acid functional polymerizable, ethylenically unsaturated monomers; (3) 0 to 10 percent by weight of one or more polymerizable monomers having one or more functional groups capable of reacting to form crosslinks; and (4) one or more polymerizable ethylenically unsaturated monomers. Each of (1), (2), (3) and (4) are different one from the other and at least one of (3) and (4) is present in the monomeric composition. Multi-layer composite coatings and coated substrates also are provided.

1. A multi-layer composite coating comprising a basecoat deposited from at least one basecoat film-forming composition and a topcoat composition applied over at least a portion of the base coat in which the topcoat is deposited from at least one topcoat film forming composition that is substantially free of organic solvent, the topcoat film-forming composition comprising:
 an aqueous dispersion of polymeric microparticles prepared by emulsion polymerization of a monomeric composition comprising: 
 (1) at least 10 percent by weight of one or more vinyl aromatic compounds; 
 (2) 0.1 to 10 percent by weight of one or more carboxylic acid functional polymerizable, ethylenically unsaturated monomers; 
 (3) 0 to 10 percent by weight of one or more polymerizable monomers having one or more functional groups which are capable of reacting to form crosslinks; and 
 (4) one or more polymerizable, ethylenically unsaturated monomers, 
 where the weight percentages are based on total weight of monomers present in the monomeric composition; 
 wherein each of (1), (2), (3) and (4) are different one from the other and wherein at least one of (3) and (4) is present in the monomeric composition; and 
 wherein the topcoat film-forming composition comprises a material comprising a reactive-functional group-containing polysiloxane; and wherein the material comprising the reactive-functional group-containing polysiloxane is different from the microparticles of the aqueous dispersion. 
 
     
     
       2. The multi-layer composite coating of  claim 1 , wherein the base coat film-forming composition comprises one or more pigments. 
     
     
       3. The multi-layer composite coating of  claim 1 , wherein the topcoat film-forming composition is substantially free of pigments. 
     
     
       4. The multi-layer composite coating of  claim 1 , wherein the topcoat film-forming composition further comprises inorganic particles selected from fumed silica, amorphous silica, alumina, colloidal alumina, titanium dioxide, zirconia, colloidal zirconia, and mixtures thereof. 
     
     
       5. The multi-layer composite coating of  claim 4 , wherein the inorganic particles have an average particle size ranging from 1 to 1000 nanometers prior to incorporation into the topcoat film-forming composition. 
     
     
       6. The multi-layer composite coating of  claim 4 , wherein the inorganic particles have an average particle size ranging from 1 to 10 microns prior to incorporation into the topcoat film-forming composition. 
     
     
       7. The multi-layer composite coating of  claim 1 , wherein the one or more vinyl aromatic compounds (1) comprises a compound selected from the group consisting of styrene, alpha-methyl styrene, vinyl toluene, para-hydroxy styrene and mixtures thereof. 
     
     
       8. The multi-layer composite coating of  claim 1 , wherein the one or more vinyl aromatic compounds is present in the monomeric composition in an amount ranging from 10 to 98 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       9. The multi-layer composite coating of  claim 8 , wherein the one or more vinyl aromatic compounds is present in the monomeric composition in an amount ranging from 20 to 80 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       10. The multi-layer composite coating of  claim 1 , wherein the one or more carboxylic acid functional polymerizable, ethylenically unsaturated monomers (2) comprises a monomer selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, anhydrides thereof, and mixtures thereof. 
     
     
       11. The multi-layer composite coating of  claim 1 , wherein the one or more carboxylic acid functional polymerizable, ethylenically unsaturated monomers (2) is present in the monomeric composition in an amount ranging from 0.5 to 8 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       12. The multi-layer composite coating of  claim 11 , wherein the one or more carboxylic acid functional polymerizable, ethylenically unsaturated monomers (2) is present in the monomeric composition in an amount ranging from 1 to 5 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       13. The multi-layer composite coating of  claim 1 , wherein the one or more polymerizable monomers having functional groups which are capable of reacting to form crosslinks after polymerization (3) comprise functional groups selected from amide groups, hydroxyl groups, amino groups, epoxy groups, thiol groups, isocyanate groups, carbamate groups, and mixtures thereof. 
     
     
       14. The multi-layer composite coating of  claim 1 , wherein the one or more polymerizable monomers having functional groups which are capable of reacting to form crosslinking (3) comprise a compound selected from γ-(meth)acryloxytrialkoxysilane, N-methylol(meth)acrylamide, N-butoxymethyl(meth)acrylamide, (meth)acryliclactones, N-substituted (meth)acrylamide lactones, (meth)acryliclactams, N-substituted (meth)acrylamide lactams, and glycidyl (meth)acrylate, and mixtures thereof. 
     
     
       15. The multi-layer composite coating of  claim 1 , wherein the one or more polymerizable monomers having functional groups which are capable of reacting to form crosslinks (3) are present in the monomeric composition in an amount ranging from 0.5 to 8 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       16. The multi-layer composite coating of  claim 15 , wherein the one or more polymerizable monomers having functional groups which are capable of reacting to form crosslinks (3) is present in the monomeric composition in an amount ranging from 1 to 5 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       17. The multi-layer composite coating of  claim 1 , wherein the one or more polymerizable, ethylenically unsaturated monomers (4) are present in the monomeric composition in an amount ranging from 0.5 to 50 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       18. The multi-layer composite coating of  claim 17 , wherein the one or more polymerizable, ethylenically unsaturated monomers (4) are present in the monomeric composition in an amount ranging from 20 to 40 percent by weight based on total weight of monomers present in the monomeric composition. 
     
     
       19. The multi-layer composite coating of  claim 1 , wherein the polymeric microparticles have an average particle size ranging from 800 to 10,000 Angstroms. 
     
     
       20. The multi-layer composite coating of  claim 1 , wherein the aqueous dispersion of polymeric microparticles is present in the topcoat film-forming composition an amount ranging from 1.0 to 20 percent by weight based on total weight of resin solids present in the topcoat film-forming composition. 
     
     
       21. The multi-layer composite coating of  claim 20 , wherein the aqueous dispersion of polymeric microparticles is present in the topcoat film-forming composition an amount ranging from 1.0 to 15 percent by weight based on total weight of resin solids present in the topcoat film-forming composition. 
     
     
       22. The multi-layer composite coating of  claim 1 , wherein the topcoat film-forming composition comprises a thermosetting composition. 
     
     
       23. The multi-layer composite coating of  claim 1 , wherein the topcoat film-forming composition comprises a thermoplastic composition. 
     
     
       24. The multi-layer composite coating of  claim 22 , wherein the topcoat film-forming composition further comprises (a) a resinous binder system comprising a reactive functional group-containing polymer, and (b) a crosslinking agent having functional groups reactive with the functional groups of the polymer. 
     
     
       25. The multi-layer composite coating of  claim 24 , wherein the resinous binder (a) comprises a second aqueous dispersion of polymeric microparticles. 
     
     
       26. The multi-layer composite coating of  claim 25 , wherein the second aqueous dispersion of polymeric microparticles comprises: (i) at least one substantially hydrophobic polymer having reactive functional groups; and (ii) at least one substantially hydrophobic crosslinking agents having functional groups reactive with the functional groups of the polymer (i). 
     
     
       27. A substrate comprising
 a substrate, and 
 the multi-layer composite coating of  claim 1  over at least a portion of the substrate. 
 
     
     
       28. A multi-layer composite coating comprising a basecoat deposited from at least one basecoat film-forming composition and a topcoat composition applied over at least a portion of the base coat in which the topcoat is deposited from at least one topcoat film forming composition that is substantially free of organic solvent, the topcoat film-forming composition comprising:
 an aqueous dispersion of polymeric microparticles prepared by emulsion polymerization of a monomeric composition consisting of: 
 (1) at least 10 percent by weight of one or more vinyl aromatic compounds; 
 (2) 0.1 to 10 percent by weight of one or more carboxylic acid functional polymerizable, ethylenically unsaturated monomers; 
 (3) 0 to 10 percent by weight of one or more polymerizable monomers having one or more functional groups which are capable of reacting to form crosslinks; and 
 (4) one or more polymerizable, ethylenically unsaturated monomers, 
 where the weight percentages are based on total weight of monomers present in the monomeric composition; 
 wherein each of (1), (2), (3) and (4) are different one from the other and wherein at least one of (3) and (4) is present in the monomeric composition; and 
 wherein the topcoat film-forming composition comprises a material comprising a reactive-functional group-containing polysiloxane; and wherein the material comprising the reactive-functional group-containing polysiloxane is a second water dilutable additive that is different from the polymeric microparticles of the aqueous dispersion.